Before we answer that, let's ask: is there ANY religion on The Jetsons? Do they ever go to space church or something? We honestly don't remember. If the creators envisioned a religionless future, well, more power to them. Unless the just didn't want to upset the censors, avoiding the topic altogether? Anwyay...

Clearly, the titular family is not Jewish. They are supposed to be the typical Americans of the future, so no Jews are getting picked for that. George and Jane are as goyishe as it gets.

After them? Well, there are not that many characters to choose from... which brings us to Mr. Spacely. A short, angry, bald, cheap, misanthropic capitalist who owns a factory? Was voiced by Mel Blanc? Errr... let's invoke the Gargamel Law here.